TAIYUAN - At a recent international energy industry expo in Taiyuan, capital of North China's Shanxi province, local resident surnamed Jiang looked for building materials like decorations for his new apartment.

At the expo, which opened in September, Jiang was interested in marble-like tiles, made from a waste-recycling product generated from coal-burning for electric power.

An oddly-shaped, fist-sized black ball displayed at a nearby stand also grabbed Jiang's attention. It was solid fuel made of household waste, used for boiler heating and thermal power generation.

Both products are only part of the reason why the three-day expo has attracted multibillion-yuan investment and businesses from 30 countries and regions.

Agreements for 42 major projects were signed at the expo, with a combined investment volume of 62.5 billion yuan (about $9.1 billion), according to its organizers.

Most of the projects are related to advanced equipment manufacturing, new energy vehicles, energy conservation, environmental protection and the modern coal chemical industry.

The expo also highlights Shanxi's ongoing energy transformation to clean energy and the promotion of waste recycling.

"In recent years, Shanxi province, a leading producer of coal in China, has pioneered the national campaign for promoting green development," said Xuan Shengji, who works with a clean-tech company headquartered in South Korea. He came to the expo as an exhibitor.

According to local authorities, Shanxi has been promoting wide use of natural gas since 2010. By 2017, 105 counties and districts and many mining areas in the province had access to coalbed methane, benefiting 18 million residents.

"Coalbed methane, as an unconventional type of natural gas is recognized as clean energy," said Hao Pengcheng, a Shanxi-based engineer of PetroChina. "It is significant to Shanxi's energy revolution given its rich reserves and sophisticated exploitation system."

Luo Huining, secretary of the Shanxi Provincial Committee of the Communist Party of China, said at a forum during the expo: "As a significant energy base in China, Shanxi will continue to curb overcapacity and promote the use of clean and efficient energy."

By 2020, China will see a significant reduction in coal consumption. Non-fossil energy is expected to account for 35 percent to 50 percent of the total consumption by 2050, according to the Energy Research Institute of the National Development and Reform Commission.